THURSDAY, Sept. 18, 2025 (HealthDay News) -- Associations are observed between high exposure to prescribed opioid analgesics (POAs) and the risk for autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) in offspring, but much of the association is due to confounding variables, according to a study published online Sept. 16 in PLOS Medicine.Emma N. Cleary, from Indiana University in Bloomington, and colleagues examined associations between dose and duration of POA exposure during pregnancy and ASD or ADHD in children in cohorts with 1,267,978 and 918,177 children, respectively.Of the 1,267,978 children in the ASD cohort, 4.4 percent were exposed to POAs during pregnancy. The researchers found that the cumulative incidence of ASD was 2.0, 2.9, and 3.6 percent at age 10 years among children unexposed to POAs, exposed to a low dose across pregnancy, and exposed to a high dose, respectively. Cumulative maximum dose was associated with increased ASD risk in unadjusted models (hazard ratiohigh, 1.74) and when accounting for measured covariates (hazard ratiohigh, 1,34). When using alternative designs, the associations were largely or fully attenuated. In the sibling comparison, no associations were observed. When considering duration of exposure, in numerous sensitivity analyses, and in analyses of ADHD, the overall pattern of associations was also observed."While this study is not able to rule out small increased risks with high amounts of exposure, the results suggest that there is not a causal effect of prescribed opioid analgesics on risk for two common neurodevelopmental disorders, providing more data to support decision-making," Cleary said in a statement.Two authors disclosed ties to the biopharmaceutical industry.Abstract/Full Text.Sign up for our weekly HealthDay newsletter